DelimiterSyntax constructor
      
      DelimiterSyntax(})
     
    
Creates a new DelimiterSyntax which matches text on pattern.
The pattern is used to find the matching text. If requiresDelimiterRun
is passed, this syntax parses according to the same nesting rules as
emphasis delimiters.  If startCharacter is passed, it is used as a
pre-matching check which is faster than matching against pattern.
Implementation
DelimiterSyntax(
  super.pattern, {
  this.requiresDelimiterRun = false,
  super.startCharacter,
  this.allowIntraWord = false,
  this.tags,
});